(1) Field of the Invention
This invention relates to an antireflection film for preventing or minimizing reflection.
The antireflection film of the present invention is used for preventing or minimizing undesirable reflection of visible and other radiation in a transparent sheet of a display device such as a cathode ray tube and a liquid crystal display, an instrument board or panel, and an automobile windowpane.
(2) Description of the Related Art
Display devices such as a cathode ray tube and a liquid crystal display are widely used in industrial and other fields. The image quality in the display devices has been improved, but blurring or distortion of the image often occurs due to reflected images from lighting equipment. The transmittance of instrument panels, watch glasses and automobile front windowpanes is also influenced by reflected images.
As means for minimizing the undesirable surface reflection of display devices and other articles, attempts have heretofore been made wherein transparent antireflection films having different refractive indexes and specific thicknesses are formed on the transparent base sheet (for example, see U.S. Pat. No. 4,590,117). However, antireflection effects of a higher level are still desired in many display devices such as cathode ray tubes and liquid crystal displays.
In Japanese Unexamined Patent Publication 5-203804, an antireflection film is proposed which comprises a first transparent layer formed on a transparent base sheet and a second transparent layer formed on the first transparent layer, said first transparent layer having incorporated therein an appropriate coloring material so that the minimum spectral transmittance in the visible region and the minimum spectral reflectance are obtained at approximately the same wavelength.
With this antireflection film, a substantial antireflection effect is obtainable over a broad wavelength region. An interference color of a specific wavelength strongly develops, and thus, when a display device is watched for hours together, eye trouble is caused.